Control device and control method for a vehicle

ABSTRACT

At the time of the change-speed, by correcting the torque reducing portion of an output shaft during the change-speed, the revolution number of an input shaft is controlled on the basis of the corrected torque reduction correcting value. Also, the torque of said input shaft is adjusted at the end of the change-speed on the basis of said torque correcting value.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a control device for a vehicle and acontrol method for a vehicle.

[0002] Japanese Patent Application Laid-Open No.61-45163 (1986)describes a control device for a vehicle using a gear type transmission.This control device is constructed to achieve smooth speed changing byincluding a friction clutch on a gear providing the minimum change-speedratio to the gear type transmission, controlling the number ofrevolution of the input shaft of the transmission by sliding saidfriction clutch during the change-speed to synchronize it with thenumber of revolution of the output shaft of the transmission, andcorrecting torque reduction occurring during the change-speed with thetorque transmitted by said friction clutch.

[0003] However, in the prior art control device there is a problem thatif during the change-speed the control of the number of revolution onlyby using the friction clutch, a occupant would receive a sense ofincompatibility due to fluctuation of the torque of the output shaftcorrected by the friction clutch.

[0004] Also, there is a problem that, of the end of the speed, if thetorque reduction correcting value during the change-speed corrected bythe friction clutch does not match to the torque of the input shaftwhich is transmitted to the output shaft by a claw clutch, a torque stepis caused at the time of the change-speed whereby shaft vibration isgenerated after the change-speed.

SUMMARY OF THE INVENTION

[0005] An object of this invention is to improve transmission abilityfor a vehicle by suppressing the fluctuation of the torque of the outputshaft caused from the control of the number of revolution during thechange-speed and by reducing a torque step at the end of thechange-speed.

[0006] This invention relates to a control device for a vehicle whereinit has torque transmitting means between the input shaft of a gear typetransmission and the output shaft thereof, the torque transmitting meansof at least one speed changing stage is comprised by a friction clutch,the torque transmitting means of the other speed changing stages arecomprised by a dog clutch, and rid friction clutch is controlled whenthe change-speed is effected from one speed changing stage to the otherchanging stage, characterized in that said control device comprisestorque reduction correcting means for correcting, at the time of saidchange-speed, the torque reducing part of said output shaft occurringduring the change-speed, and revolution number controlling means forcontrolling the revolution number of said input shaft on the basis ofthe torque reduction correcting value corrected by said torque reductioncorrecting means.

[0007] Further, the control device according to this invention ischaracterized in that it further comprises torque adjusting means foradjusting the torque of said input shaft at the end of the change-speedon the basis of said torque reduction correcting value.

[0008] Also, this invention relates to a control method for a vehiclewherein torque transmitting means is attached between the input shaft ofa gear type transmission and the output shaft thereof, the torquetransmitting means of at least one speed changing stage is comprised bya friction clutch, the torque transmitting means of the other speedchanging stages are comprised by a dog clutch, and said friction clutchis controlled when the change-speed is effected from one speed changingstage to the other changing stage, characterized in that said controlmethod comprises the steps of correcting, at the time of saidchange-speed, the torque reducing part of said output shaft occurringduring the change-speed, and controlling the revolution number of saidinput shaft on the basis of the torque reduction correcting valuecorrected by said torque reduction correcting mean

[0009] Further, the control method according to this invention ischaracterized in that it further comprises the step of adjusting thetorque of said input shaft at the end of the change-speed on the basisof said torque reduction correcting value.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a block diagram of a vehicle system and its controldevice which is one embodiment of this invention;

[0011]FIG. 2 is a diagram showing a torque transmitting path in casewhere the vehicle is running by the driving power of an engine;

[0012]FIG. 3 is a diagram showing a torque transmitting path duringchange-speed;

[0013]FIG. 4 is a diagram showing a torque transmitting path after theend of the change-speed;

[0014]FIG. 5 is a flow chart of control processes in the torquereduction correcting means of the control device according to oneembodiment of this invention;

[0015]FIG. 6 is a flowchart of control processes in the revolutionnumber controlling means and the torque adjusting means of the controldevice according to one embodiment of this invention;

[0016]FIG. 7 is a time chart showing the control state at the time ofthe change-speed in one embodiment of this invention;

[0017]FIG. 8 is a block diagram of a control device for a vehicleaccording to the other embodiment of this invention;

[0018]FIG. 9 is a diagram showing a torque transmitting path during thechange-speed in the other embodiment of this invention;

[0019]FIG. 10 is a flow chart showing control processes in therevolution number means and the torque adjusting means of the controldevice for the vehicle according to the other embodiment of thisinvention; and

[0020]FIG. 11 is a time chart showing a control state during thechange-speed in the other embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Embodiments of this invention will be explained in detail on thebasis of the drawings.

[0022]FIG. 1 is a block diagram for a vehicle system and its controldevice according to one embodiment of this invention.

[0023] An engine 1 includes an electronically controlling throttle 2 foradjusting engine torque and a revolution or engine speed sensor 37 formeasuring the number of revolution of the engine 1, Ne. Thus, it ispossible to control the output torque of the engine with a high degreeof accuracy.

[0024] A clutch 4 is attached between the output shaft 3 of the engine 1and the input shaft 8 of a gear type transmission 50 so that the torqueof the engine 1 can be transmitted to the input shaft 8. The clutch 4 asused is of a dry single plate type, in order to control the pressingpressure of the clutch 4 a hydraulically driven actuator 32 is utilized,and power transmission from the output shaft 3 of the engine 1 to theinput shaft 8 can be interrupted by adjusting the pressing pressure ofthe clutch 4.

[0025] The input shaft 8 has gears 5, 6 and 7 attached thereto. The gear5 is used also as a detector for detecting the number of revolution ofthe input shaft 8, Nin. It is possible to detect the revolution of theinput shaft 8, by detecting the movement of the teeth of the gear 5 witha sensor 36.

[0026] A motor 27 has an output shaft 26 to which a gear 24 having aclutch 25 is connected. The gear 24 is adapted to engage with the gear 7all the time. The clutch 25 as used is of a dry single plate type whichenables the transmission of the output torque of the motor 27 to thegear 24. The control of the pressing pressure of the clutch 25 isperformed by an actuator 29 which is hydraulically driven, and powertransmission from the output shaft 26 to the input shaft 8 can beinterrupted by adjusting the pressing pressure of the clutch 25.

[0027] The gear type transmission 50 includes an output shaft 20 whichcomprises a gear 18 having a gear 14 and a synchronizer ring 16, a gear11 having a gear 12 and a synchronizer ring 15, a hub 17 directlycoupling the gear 18 and a gear 11 to the output shaft 20, and a sleeve(not shown). The gear 18 and the gear 11 have respective stoppers (notshown) for prohibiting from any movement thereof in the axial directionon the output shaft 20. Further, this hub 17 has inside grooves (notshown) engaging with a plurality of grooves (not shown) of the outputshaft 20, whereby the hub 17 is coupled to the output shaft 20 so thatthe former can relatively move axially with respect to the latter butany relative movement in the rotational direction is limited. Therefore,the torque of the hub 17 is transmitted to the output shaft 20.

[0028] In order to transmit the torque from the input shaft to the hub17, it is needed to move the hub 17 and the sleeve in the axialdirection with respect to the output shaft 20 to couple directly the hub17 to the gear 14 or the gear 12 through the synchronizer ring 16 or thesynchronizer ring 15. A hydraulically driven actuator 30 is used to movethe hub 17 and the sleeve.

[0029] The hub 17 is also used as a detector for detecting the number ofrevolution No of the output shaft 20. In this case, it is possible todetect the revolution number of the output shaft 20 by detecting therevolution of the hub 17 with a sensor 13.

[0030] A claw clutch mechanism acting as torque transmitting meanscomprising the hub 17 and the sleeve; the gear 14 and the synchronizerring 16; and the gear 12 and synchronizer ring 15 is referred to a dogclutch.

[0031] The mechanism enables to transmit energy from a power source suchas the engine 1 to a tire 23 through a differential device 21 and anaxle 22 with high efficiency, thereby to aid in decreasing fuelconsumption.

[0032] Further, the output shaft 20 includes a gear 9 having a clutch10. The clutch 10 is constituted by a wet type multiple plate typefriction clutch so that the torque of the input shaft 8 can betransmitted to the output shaft 20. The control of the pressing pressureof the clutch 10 is performed by an actuator 32 which is hydraulicallydriven, and power transmission from the input shaft 8 to the outputshaft 20 can be interrupted by adjusting this pressing pressure.

[0033] The speed changing ratio of the gear 5 and the gear 9 is madesmaller than the speed changing ratio of the gear 7 and the gear 18, andthe speed changing ratio of the gear 6 and the gear 11.

[0034] In the engine 1, the amount of intake air is controlled by theelectronically controlled throttle 2 attached to an intake pipe (notshown), and the fuel of the amount corresponding to the amount of intakeair is injected from a fuel injecting device (not shown). Also, ignitiontiming is determined on the basis of an air fuel ration defined by theamount of air and the amount of fuel as well as signals such as thenumber of revolution of the engine, Ne, and ignition is effected by anignition device (not shown).

[0035] As the fuel injection device, there are an intake port fuelinjecting system in which fuel is injected to an intake port, and acylinder fuel injecting system in which fuel is injected directly into acylinder, but it is preferable to select a system which enables todecrease fuel consumption and is superior to exhaust gas ability,comparing operation areas (areas determined by the engine torque and theengine revolution number) required by the engine.

[0036] Next, a control device 100 will be explained for controlling theengine 1, the actuators 29, 30, 31 and 32, and the motor 27.

[0037] The control device 100 receives as input signals an accelerationpedal controlling amount signal, a shift lever position signal Ii, anengine revolution number signal Ne detected by a sensor 37, an inputshaft revolution number signal Nin detected by a sensor 36 and an outputshaft revolution number signal No detected by a sensor 13. In responsethereto, the control device 100 computes the torque Te of the engine 1,and sends it to a control device 34 through a LAN constitutingcommunication means.

[0038] The control device 34 computes the degree of throttle valveopening, the amount of fuel and ignition timing for achieving thereceived engine torque, and controls respective actuators (for example,the electronically controlled throttle 2).

[0039] Also, the control device 100 computes the torque and the numberof revolution of the motor 27, and sends them to a control device 35through the LAN to control the motor. The control device 35 functions tocharge a battery 28 with power obtained from the motor 27 and supply apower from the battery 28 to the motor 27 for driving it.

[0040] The control device 100 comprises vehicle speed detecting means101, change-speed command generating means, torque reduction correctingmeans 103, revolution number controlling means 104 and torque adjustingmeans 105.

[0041] The vehicle speed detecting means 101 computes the vehicle speedVsp on the basis of the output shaft revolution number No detected bythe sensor 13 (in this case, the computation is performed as Vsp=f(Nm)using function f)

[0042] The change-speed command generating means 102 determines a speedchanging command Ss on the basis of the input accelerator pedalcontrolling amount and the vehicle speed Vsp found by the vehicle speeddetecting means 101. The speed changing command Ss is selected fromvalues stored in memory means (not shown) within the control device 100,said values being found by a pre-experiment or a simulation as onesgiving the maximum efficiency to the engine 1 and motor 27.

[0043] Now, the control of the clutch 10 will be explained when thespeed changing stages is altered (speed changed) from first (1) speedoperation state to second speed (2) operation state, using FIG. 2, FIG.3 and FIG. 4. The control of the clutch 10 is effected by controllingthe actuators 29 to 32 on the basis of the commands from the controldevice 100 so that the control device 33 controls the gear typetransmission 50.

[0044]FIG. 2 is a view for explaining the first state operation speed incase where the vehicle is intended to be accelerated when it runs withthe driving force of the engine 1. In the drawings, dotted arrow linesindicate torque transmitting paths. As one example, it is assumed wherethe clutch 4 has been coupled and the dog clutch (hub 17) has beencoupled to the gear 18. In this condition, the torque of the engine 1 istransmitted to the output shaft 20 trough the clutch 4, the input shaft8, the gear 7 and the gear 18. At that time, the clutch 10 is in thereleased condition.

[0045] When the change-speed command Ss is output by the change-speedcommand generating means 102, the dog clutch (hub 17) is made thereleased condition to release the coupling between the gear 18 and theoutput shaft 20, as shown in FIG. 3. At the same time, the actuator 31is controlled to press and couple the clutch 10, thereby to transmit thetorque of the engine 1 from the output shaft 3 through the clutch 4.,the input shaft 8, the gear 5, the gear 9 and the clutch 10 to theoutput shaft 20. Thus, when the torque of the engine 1 is transmitted tothe axle 22 with the pressing pressure of the clutch 10 to make it thedriving torque for the vehicle, the gears 5 and 9 are used and the speedchanging ratio becomes smaller. As a result, the load of the engine 1becomes larger and the number of revolution decreases, whereby the speedchanging ratio between the output shaft 20 and the input shaft 8 leavesthe speed changing ratio of the first speed and approaches to the speedchanging ratio of the second speed (the direction that the speedchanging ratio becomes smaller).

[0046] Then, when the speed changing ratio between the input shaft 8 andthe output shaft 20 becomes the change-speed ratio of the second speed,the dog clutch (hub 17) is coupled to the gear 11 to couple the gear 11to the output shaft 20, as shown in FIG. 4. As soon as this coupling iscompleted, the actuator 31 is controlled so that the change-speed fromthe first speed to the second speed is completed by releasing thepressing pressure of the clutch 10. In this second speed operationstate, the torque of the engine 1 is transmitted through thetransmitting path passing the output shaft 3 of the engine 1, the clutch4, the input shaft 8, the gear 6, the gear 11, the hub 17 and the outputshaft 20 in the order.

[0047] From the above-mentioned explanation, it is appreciated thatalthough at the time of the change-speed a neutral state is created byreleasing the first speed condition, since at that time the torque ofthe engine 1 is adapted to be transmitted to the axle 22 by the clutch10 and the gears 5 and 9, it is possible to correct any torque reductionoccuring during this change-speed.

[0048] Now, a control method at the time of the change-speed in thevehicle control device of this embodiment will be explained by usingFIG. 5 to FIG. 7.

[0049] First, control processes in the torque reduction correcting means103 will be explained.

[0050]FIG. 5 is a flow chart for the control processes in the torquereduction correcting means 103.

[0051] Step 501

[0052] In this step, a change-speed command Ss output from thechange-speed command generating means 102 is read.

[0053] Step 502

[0054] In this step, the torque Tel of the engine 1 before thechange-speed (during the first speed), received by the control device 34through the LAN is read.

[0055] Step 503

[0056] In this step, the torque Tout1 of the output shaft 20 before thechange-speed (during the first speed) is computed on the basis of thetorque Tel of the engine 1 before the change-speed, read in Step 502.

[0057] In this step, the FF (Feed Forward) target torque Tc_ff of theclutch 10 is computed on the basis of the torque Tout1 of the outputshaft 20 computed in Step 503. Also, assuming that the change-speedratio at the first speed is referred to R1, the change-speed ratio atthe second speed is referred to R2, the engine revolution number beforethe change-speed is referred to Ne1 and the engine revolution numberafter the change-speed (at the time of the second speed) is referred toNe2, the engine revolution number Ne2 after the change-speed may bepresumed as Ne2 Ne1×(R2/R1). Further, it is possible to find the enginetorque after the change-speed in response to the presumed enginerevolution number Ne2 and the amount of throttle opening, and the outputshaft torque after the change-speed, Tout 2 can be also presumed. It ispossible to compute the FF target torque Tc_ff of the clutch 10depending upon this presumed torque Tout2.

[0058] Step 505

[0059] In this step, it is determined whether an input/output shaftrevolution number ratio Rch which is found by the engine revolutionnumber Ne (input shaft revolution number Nin) and the output shaftrevolution number No is within a predetermined range. If it is notwithin the predetermined range, the process proceeds to Step 506, and ifit is within the predetermined range, the process proceeds to Step 508.

[0060] Step 506

[0061] In this step, in case where during the change-speed theinput/output shaft revolution number ratio Rch is not within thepredetermined range, the torque reduction correcting value during thechange-speed, Tc_ref is computed as Tc_ref=Tc_ff.

[0062] Step 507

[0063] In this step, in case where during the change-speed theinput/output shaft revolution number ratio Rch is within thepredetermined range, by feeding back an error between the targetrevolution number ratio corresponding to the change-speed ratio of thesecond speed and the input/output shaft revolution number ratio Rch, therevolution number ratio FB (Feed Back) target torque Tc_fb is computed.At that time, the revolution number ratio FB target Tc_fb of the clutch10 may be computed by computing the target engine revolution number(input shaft revolution number) depending upon the target revolutionnumber ratio and feeding back the engine revolution number Ne.

[0064] Step 508

[0065] In this step, the torque reduction correcting value Tc_ref duringthe change-speed is computed as Tc_ref=Tc_ff+Tc_fb.

[0066] Step 509

[0067] In this step, the torque reduction correcting value Tc_ref duringthe change-speed Tc_ref found in Step 506 and Step 508 is output as thetarget torque of the clutch 10. The output torque reduction correctingvalue Tc_ref is sent to the control device 33 through the LAN.

[0068] The control device 33 is a control device for drivinghydraulically the actuators 29 to 33, and controls the actuator 31,thereby to correct any torque reducing part during the change-speed onthe basis of the value of Tc_ref by adjusting the pressing pressure ofthe clutch 10.

[0069] As explained above, in the torque reduction correcting means, itis possible to improve change-speed ability by correcting the torquereducing portion of the output shaft 20 occurring during thechange-speed.

[0070] Next, control processes in the revolution number controllingmeans 104 and the torque adjusting means 105 will be explained.

[0071]FIG. 6 is a flow chart for the control processes in the revolutionnumber controlling means 104 and the torque adjusting means 105.

[0072] Step 601

[0073] In this step, it is determined whether the input/output shaftrevolution number ratio Rch found on the basis of the engine revolutionnumber Ne (input shaft revolution number Nin) and the output shaftrevolution number No is within a predetermined range. If it is notwithin the predetermined range, the process proceeds to Step 602 inwhich control processes are preformed by the revolution numbercontrolling means 104, and if it is within the predetermined range, theprocess proceeds to Step 603 in which control processes are performed bythe torque adjusting means 105.

[0074] First, control processes in the revolution number controllingmeans 104 which are effected in Step 602 to Step 604 will be explained.

[0075] Step 602

[0076] In this step, the torque reduction correcting value Tc_ref foundaccording to Tc_ref=Tc_ff is read.

[0077] Step 603

[0078] In this step, the target torque of the engine 1, Te_ref1achieving the revolution number Ne of the engine 1, Ne giving thepredetermined input/output shaft revolution number ratio Rch is computedon the basis of the torque reduction correcting value Tc_ref as read inStep 602.

[0079] Step 604

[0080] In this step, the target torque Te_ref 1 of the engine 1 found inStep 603 is output. The output target torque Te_ref1 of the engine1 issent to the control device 34 through the LAN.

[0081] The control device 34 controls the electronically controlledthrottle 2 so that the target torque Te-ref1 of the engine 1 isachieved.

[0082] Also, in the revolution number controlling means 104, in order toachieve the target torque Te_ref1 of the engine 1, the air fuel ratio ofthe engine 1 may be controlled, or ignition timing may be controlled.

[0083] As explained above, in the embodiment, it is possible to couplethe dog clutch as the second condition by controlling the revolutionnumber of the input shaft 8 during the change-speed using the revolutionnumber controlling means 104, and also to improve change-speed abilityby controlling inertia torque at the time of the coupling to the secondspeed.

[0084] Next, control processes in the torque controlling means 105effected in Step 605 to Step 607 will be explained.

[0085] Step 605

[0086] In this step, the torque reduction correcting value Tc_ref foundaccording to Tc_ref=Tc_ff+Tc_fb is read.

[0087] Step 606

[0088] In this step, the target torque Te_ref2 of the engine 1, makingsmaller a deviation between the output shaft torque after thechange-speed and the torque reduction correcting value Tc_ref iscomputed on the basis of the torque reduction correcting value Tc_refread in Step 605.

[0089] Step 607

[0090] In this step, the target torque Te_ref2 of the engine 1 found inStep 606 is output. The output target torque Te_ref2 of the engine1 issent to the control device 34 through the LAN.

[0091] The control device 34 controls the electronically controlledthrottle 2 so that the target torque Te_ref2 of the engine 1 isachieved.

[0092] Also, in the torque adjusting means 105, in order to achieve thetarget torque Te_ref2 of the engine 1, the air fuel ratio of the engine1 may be controlled, or ignition timing may be controlled.

[0093] As explained above, in the torque adjusting means 105, it ispossible to make smaller the deviation between the torque reductioncorrecting value during the change-speed and the torque of the outputshaft 20 after the change-speed by controlling the torque of the inputshaft 8 at the end of the change-speed, and also it is possible toimprove speed changing ability by decreasing the torque step thereby torestrain any shaft vibration or fluctuation after the change-speed.

[0094] Next, the operation at the time of the change-speed will beexplained.

[0095]FIG. 7 is a time chart showing the control condition at the timeof the change-speed. In FIG. 7, (A) shows a speed changing command Ss,(B) a shift lever position corresponding to a dog clutch position, (C)the input/output shaft revolution number ratio Rch, (D) the degree ofthrottle openingθ, (E) the torque Tc of the clutch 10, and (F) thetorque Tout of the output shaft 20. Also, the axis of abscissarepresents time.

[0096] As shown in (A), when during the driving at the first speed thechange-speed command Ss instructing the second speed is output at pointa, the speed changing control is started, and as shown in (E) the torqueTc of the clutch 10 gradually increases.

[0097] As the torque Tc of the clutch 10 gradually increases, as shownin (F) the torque Tout of the output shaft 20 gradually decreases and atpoint b, the dog clutch which has been coupled at the first speed sidebecomes releasable condition. This is because due to the torque to betransmitted with the gears 5 and 9 the torque to be transmitted with thegear 7 and 18 decreases up to the value making the dog clutchreleasable.

[0098] When the dog clutch becomes the releasable condition, the dogclutch which has been coupled at first speed side is released by thecontrol of the actuator 30, and the shift lever position Ii becomes aneutral state (during the change-speed), whereby the actual change-speedis initiated.

[0099] When the shift lever position Ii becomes the neutral state, asshown in (E) the control of the clutch 10 for correcting the torquereduction part occurring during the change-speed is started, and theactuator 31 is controlled in accordance with the value of the targettorque Tc_ref=Tc_ff of the clutch 10 output from the torque reductioncorrecting means 103, whereby as shown in (F) any torque reduction partof the output shaft 20 during the change-speed is corrected.

[0100] At that time, since the torque transmitted by the clutch 10becomes equal to the torque of the output shaft 20, it is preferablethat the target torque Tc_ref of the clutch 10 has a smooth property toreduce the sense of discomfort which an occupant would receive. Also, itis needed to control, during the change-speed, the input/output shaftrevolution number ratio Rch rapidly and smoothly so that it becomes thespeed changing ratio R2 of the second speed.

[0101] Therefore, in order to obtain the target torque Te_ref1 of theengine 1 output by the revolution number controlling means 104, theengine revolution number Ne is adjusted by controlling the throttleopening so that it becomesθ=-θ_ref1 as shown in (D), whereby theinput/output revolution number ratio Rch is caused to be close to thespeed changing ratio R2 of the second speed.

[0102] By such control of the clutch 10 and the electronicallycontrolled throttle 2, as shown in (C) the input/output shaft revolutionnumber ratio Rch becomes Rch=R2 at point c, but it is preferable that tocause the dog clutch to couple, the engine revolution number Ne ischanged toward its increase, thereby to match the input/output shaftrevolution number ratio Rch to the speed changing ratio R2. This isdisadvantageous that since the number of revolution No of the outputshaft 20 has been increased by the torque reduction correcting valuecorrected during the change-speed, if the dog clutch is tried to becoupled at the time when the revolution number of the input shaft 8 isin the direction of its decrease, torque interference occurs at thebiting portions of the dog clutch, which makes the coupling defficult.This is because the way by which the dog clutch is coupled in thedirection in which the number of revolution of the input shaft 8increases gives lesser torque interference.

[0103] Since after point c the relationship between Rch and R2 becomesRch<R2, it is needed to increase the input/output shaft revolutionnumber ratio Rch. However, since just before the coupling (between pointc and point d), with the control of the engine torque Te a slight delayoccurs in its response, it is preferable to adjust the input/outputshaft revolution number ratio Rch with the torque of the clutch 10. Tothis end, during the period from point c to point d, the revolutionnumber ratio FB target torque Tc_fb depending upon the deviation betweenthe input/output shaft revolution number ratio Rch and the speedchanging ratio R2 at the second speed is added, thereby to set thetarget torque of the clutch 10 to Tc_ref=Tc_ff+Tc_fb.

[0104] As described above, by feeding back the input/output shaftrevolution number ratio during only a period in which the deviationbetween the input/output shaft revolution number ratio Rch and the speedchanging ratio at the second speed is small, it is possible to restrain,to the minimum, the torque variation of the torque reduction correctingvalue occurring during the change-speed and it is possible to assuagethe sense of discomfort which the occupant receives. By such revolutionnumber ratio FB control of the clutch 10, the relationship of Rch R2occurs in the direction in which the input/output shaft revolutionnumber ratio Rch increases, and the dog clutch becomes the condition inwhich it can be coupled at the second speed.

[0105] When the dog clutch becomes the condition in which it can becoupled at the second speed, the control of the actuator 30 results inthe coupling of the dog clutch at the second speed. However, at thattime, it is preferable that by make smaller the deviation between thetorque reduction correcting value Tc_ref−Tc_ff+Tc_fb during thechange-speed and the torque of the output shaft 20 after thechange-speed (after the coupling at the second speed), the torque stepof the output shaft 20 at the end of the change-speed is reduced,thereby to suppress the occurrence of the shaft vibration.

[0106] Since the torque reduction correcting value during thechange-speed is determined by the torque Tc of the clutch 10 and thetorque of the output shaft 20 after the change-speed is determined bythe torque Te of the engine 1 and the speed changing ratio R2 at thesecond speed, between point c and point d the throttle opening iscontrolled so that it becomes θ=θ_ref2, so as thereby to achieve thetarget torque Te_ref2 of the engine 1. Since during the change-speed theclutch 10 is under a slippage condition, if the torque Te of the engine1 is larger than a predetermined value, the torque reduction correctingvalue during the change-speed is determined by the torque Tc of theclutch 10 and the inertia torque of the engine 1, whereby it is possibleto perform the torque matching control at the end of the change-speedindependently of the torque reduction correcting control during thechange—speed.

[0107] When at point d the actual change-speed is completed by the factthat the dog clutch is coupled to the second speed, the throttleopeningθ is returned gradually to the opening before the change-speedand at point e the speed changing control is finished.

[0108] As explained above, in accordance with this embodiment, in thespeed changing operation by finding the torque reduction correctingvalue of the output shaft 20 during the change-speed, controlling therevolution number of the input shaft 8 on the basis of this torquereduction correcting value, and at the end of the change-speed adjustingthe torque of the input shaft 8, the torque variation of thetransmission output shaft 20 can be suppressed.

[0109] Next, a construction of the control device for a vehicleaccording to the other embodiment of this invention will be explainedusing FIG. 8 to FIG. 11.

[0110]FIG. 8 is a block diagram for the control device according to thisembodiment. Since the overall system construction of the vehicle is thesame as one in the embodiment shown in FIG. 1, its explanation isabbreviated. Also, constructive parts in this embodiment equivalent tothe constructive parts in the embodiment in FIG. 1 will be explainedaffixing thereto the same reference numerals.

[0111] A control device 800 comprises the vehicle speed detecting means101, the change-speed command generating means 102, the torque reductioncorrecting means 103, revolution number controlling means 801 and torqueadjusting means 802.

[0112] Since the control processes preformed in the vehicle speeddetecting means 101 and the change-speed command generating 102 aresimilar to those in the embodiment shown in FIG. 1, the explanationtherefor is abbreviated.

[0113] Now, the control for the clutch 10 and the motor 27 at the timewhen the change-speed is carried out from the first speed operationstate to the second speed operation state will be explained using FIG.9.

[0114] When the change-speed command Ss is output by the change-speedcommand generating means 102, the dog clutch (hub 17) is made theuncoupled condition to release the coupling between the gear 18 and theoutput shaft 20, as shown in FIG. 9. At that time, the clutch 25 hasbeen made the coupled condition by the control of the actuator 29. Atthat time, the torque of the motor 27 is transmitted along a motortorque transmitting path passing the output shaft 26 of the motor 27,the clutch 25, the gear 24, the gear 7, the input shaft 8, the gear 5,the gear 9, the clutch 10 and the output shaft 20 in the order, wherebythe revolution number control and the torque adjustment for the inputshaft 8 by the motor 27 becomes possible.

[0115] During the change-speed, the torque of the engine 1 istransmitted to the output shaft 20 through the gears 5 and 9 by pressingthe clutch 10 under the control of the actuator 31. By this pressingpressure for the clutch 10 the torque of the engine 1 is transmitted tothe axle 22 to be used as the driving torque of the vehicle, and therevolution number of the engine 1 is decreased because the load of theengine 1 becomes larger as a result of the small speed changing ratio bythe use of the gears 5 and 9, whereby the speed changing ratio betweenthe output shaft 20 and the input shaft 8 approaches the speed changingratio of the second speed (the sense in which it becomes smaller) fromthe speed changing ratio of the first speed.

[0116] At that time, the torque of the engine 1 is transmitted along atransmitting path passing the output shaft 3 of the engine 1, the clutch4, the input shaft 8, the gear 5, the gear 9, the clutch 10 and theoutput shaft 20 in the order. Then, when the speed changing ratiobetween the input shaft 8 and the output shaft 20 becomes the speedchanging ratio of the second speed, the gear 11 and the output shaft 20are coupled by coupling the dog clutch to the gear 11. As soon as thedog clutch is coupled to the second speed state, the actuator 31 iscontrolled to release the pressing pressure of the clutch 10, wherebythe change-speed is completed.

[0117] As mentioned above, although at the time of the change-speed theneutral state occurs by releasing the first speed, since at that timethe torque of the engine 1 and the motor 27 is transmitted to the axle22 through the output shaft 20 by the clutch 10 and the gear 5 and 9, itis possible to correct any torque reducing portion occurring during thechange-speed.

[0118] Now, a control method at the time of the change-speed in thecontrol device for a vehicle according to this embodiment will beexplained using FIG. 10 and FIG. 11. Incidentally, since the controlprocesses in the torque reduction correcting means 103 are equivalent tothose explained using FIG. 5, the explanation therefor is abbreviated.

[0119] First, control processes in the revolution number controllingmeans 801 and the torque adjusting means 802 will be explained usingFIG. 10. FIG. 10 is a flow chart for the control processes performed inthe revolution number controlling means 801 and the torque adjustingmeans 802.

[0120] Step 1001

[0121] In this step, it is determined whether the input/output shaftrevolution number ratio Rch found on the basis of the engine revolutionnumber Ne (input shaft revolution number Nin) and the output shaftrevolution number No is within a predetermined range. If it is notwithin the predetermined range, the process proceeds to Step 1002 inwhich the control by the revolution number controlling means 801 ispreformed, and if it is within the predetermined range, the processproceeds to Step 1005 in which the control process by the torqueadjusting means 802 is performed.

[0122] First, control processes in the revolution number controllingmeans 801 which are performed in Step 1002 to Step 1004 will beexplained.

[0123] Step 1002

[0124] The torque reduction correcting value Tc_ref found byTc_ref=Tc_ff is read.

[0125] Step 1003

[0126] The target torque Tm_ref1 of the motor 27 which achieves therevolution number Ne of the engine 1 effectuating a predeterminedinput/output shaft revolution Rch is computed on the basis of the torquereduction correcting value Tc_ref read in Step 1002.

[0127] Step 1004

[0128] In this step, the target torque Tm_ref1 of the motor 27 found inStep 1003 is output. The output target torque Tm_ref 1 of the motor 27is sent to the control device 35 through the LAN.

[0129] The control device 35 controls the motor 27 and the battery 28 toachieve the target torque Tm_ref1 of the motor 27.

[0130] As explained above, in the revolution number controlling means801, it is possible to couple the dog clutch to the second speed bycontrolling the revolution number of the input shaft 8 during thechange-speed and it is also possible to improve speed changing abilityby suppressing the inertia torque occurring at the time of the secondspeed coupling.

[0131] Next, control processes in the torque adjusting means 802preformed in Step 1005 to Step 1007 will be explained.

[0132] Step 1005

[0133] In this step, the torque reduction correcting value Tc_reffounded by Tc_ref=Tc_ff+Tc_fb is read.

[0134] In this step, on the basis of the torque reduction correctingvalue Tc_ref read in Step 1005, the target torque Tm_ref2 of the motor27 which makes smaller the deviation between the output shaft torqueafter the change-speed and the torque reduction correcting value Tc_refis computed.

[0135] Step 1007

[0136] In this step, the target torque Tm_ref2 of the motor 27 found inStep 1006 is output. The output target torque Tm_ref2 of the motor 27 issent to the control device 35 through the LAN.

[0137] The control device 35 controls the motor 27 and the battery 28 toachieve the target torque Tm_ref2 of the motor 27.

[0138] As explained above, in the torque adjusting means 802, bycontrolling the torque of the input shaft 8 at the end of thechange-speed, it is possible to make smaller the deviation between thetorque reduction correcting value during the change-speed and the torqueof the output shaft 20 after the change-speed, and it is also possibleto improve speed changing ability by reducing the torque step, therebyto suppress any shaft vibration occurring after the change-speed.

[0139] Next, the operation at the time of change-speed will beexplained.

[0140]FIG. 11 is a time chart showing a control state at the time of thechange-speed. In FIG. 11, (A) indicates a change-speed command Ss, (B) ashift lever position Ii corresponding to a dog clutch position, (C) aninput/output shaft revolution number ratio Rch, (D) the torque Tm of themotor 27, (E) the torque Tc of the clutch 10 and (F) the torque Tout ofthe output shaft 20. Also, the abscissa of this time chart indicatestime.

[0141] As shown in (A), when the speed changing command Ss instructingthe second speed is output at point a during traveling at the firstspeed, speed changing control is started, whereby as shown in (E) thetorque Tc of the clutch 10 gradually increases.

[0142] As the torque Tc of the clutch 10 increases, as shown in (F) thetorque Tout of the output shaft 20 gradually decreases and at point bthe dog clutch which is being coupled at the first speed side becomes areleasable state. This is because by the torque transmitted with thegears 5 and 9, the torque transmitted with the gear 7 and 18 decreasesup to a value making the dog clutch releasable.

[0143] When the dog clutch becomes the releasable state, by the controlof the actuator 30 the dog clutch which has been coupled at the firstspeed side is released, whereby as shown in (B) the shift lever positionIi becomes a neutral state (during the change-speed) and the actualchange-speed is started.

[0144] When the shift lever position Ii becomes the neutral state, asshown in (E) the control of the clutch 10 for correcting the torquereduction part occurring during the change-speed is started, and theactuator 31 is controlled in accordance with the value of the targettorque Tc_ref=Tc_ff of the clutch 10 output from the torque reductioncorrecting means 103, whereby as shown in (F) any torque reduction partof the output shaft 20 during the change-speed is corrected.

[0145] At that time, since the torque transmitted by the clutch 10becomes equal to the torque of the output shaft 20, it is preferablethat the target torque Tc_ref of the clutch 10 has a smooth property toreduce the sense of discomfort which an occupant would receive. Also, itis needed to control, during the change-speed, the input/output shaftrevolution number ratio Rch rapidly and smoothly so that it becomes thespeed changing ratio R2 of the second speed.

[0146] Therefore, as shown in (D), the motor 27 and the battery 28 arecontrolled to obtain the target torque Te_ref1 of the motor 27 output bythe revolution number controlling means 801, thereby to adjust theengine revolution number Ne, whereby the input/output revolution numberratio Rch is caused to be close to the speed changing ratio R2 of thesecond speed.

[0147] By such control of the clutch 10 and the motor 27, as shown in(C) the input/output shaft revolution number ratio Rch becomes Rch=R2 atpoint c, but it is preferable that to cause the dog clutch to couple,the engine revolution number Ne is changed toward its increase, therebyto match the input/output shaft revolution number ratio Rch to the speedchanging ratio R2. This is disadvantageous that since the number ofrevolution No of the output shaft 20 has been increased by the torquereduction correcting value corrected during the change-speed, if the dogclutch is tried to be coupled at the time when the revolution number ofthe input shaft 8 is in the direction of its decrease, torqueinterference occurs at the biting portions of the dog clutch, whichmakes the coupling difficult. This is because the way by which the dogclutch is coupled in the direction in which the number of revolution ofthe input shaft 8 increases gives lesser torque interference.

[0148] Since after point c the relationship between Rch and R2 becomesRch<R2, it is needed to increase the input/output shaft revolutionnumber ratio Rch. However, immediate before the coupling (during pointsc to d), both of the torque and the revolution number of the motor 27must be controlled. If as the motor 27 a motor that merely can carry outonly one of the torque control and the revolution has been selected, itis needed that the input/output shaft revolution number ratio Rch beadjusted by the torque of the clutch 10. To this end, during the periodfrom point c to point d, the revolution number ratio FB target torqueTc_fb depending upon the deviation between the input/output shaftrevolution number ratio Rch and the speed changing ratio R2 at thesecond speed is added, thereby to set the target torque of the clutch 10to Tc_ref=Tc_ff+Tc_fb.

[0149] As described above, by feeding back the input/output shaftrevolution number ratio during only a period in which the deviationbetween the input/output shaft revolution number ratio Rch and the speedchanging ratio of the second speed is small, it is possible to restrain,to the minimum, the torque variation of the torque reduction correctingvalue occurring during the change-speed and it is possible to assuagethe sense of discomfort which the occupant receives. By such revolutionnumber ratio FB control of the clutch 10, the relationship of Rch R2occurs in the direction in which the input/output shaft revolutionnumber ratio Rch increases, and the dog clutch becomes the condition inwhich it can be coupled at the second speed.

[0150] When the dog clutch becomes the condition in which it can becoupled at the second speed, the control of the actuator 30 results inthe coupling of the dog clutch at the second speed. However, at thattime, it is preferable that by make smaller the deviation betweenTc_ref−Tc_ff+Tc_fb corresponding to the torque reduction correctingvalue during the change-speed and the torque of the output shaft 20after the change-speed (after the coupling at the second speed), thetorque step of the output shaft 20 at the end of the change-speed isreduced, thereby to suppress the occurrence of the shaft vibration.

[0151] Since the torque reduction correcting value during thechange-speed is determined by the torque Tc of the clutch 10 and thetorque of the output shaft 20 after the change-speed is determined bythe torque Te of the engine 1, and the torque Tm of the motor 27 and thespeed changing ratio R2 at the second speed, between point c and point dthe motor 27 and the the battery 28 are is controlled so that the targettorque Tm_ref2 of the motor 27 is achieved. Since during thechange-speed the clutch 10 is under a slippage condition, if the sum ofthe torque Te of the engine 1 the torque Tm of the motor 27 is largerthan a predetermined value, the torque reduction correcting value duringthe change-speed is determined by the torque Tc of the clutch 10 and theinertia torque of the engine 1 and the motor 27, whereby it is possibleto perform the torque matching control at the end of the change-speedindependently of the torque reduction correcting control during thechange-speed.

[0152] At point d the actual change-speed is completed by the fact thatthe dog clutch is coupled to the second speed. After the completion ofthe change-speed, the torque TM of the motor 27 is returned to zerogradually, and at point e the speed changing control finishes.

[0153] As explained above, in accordance with this embodiment, in thespeed changing operation, by finding the torque reduction correctingvalue of the output shaft 20 during the change-speed, controlling therevolution number of the input shaft 8 on the basis of this torquereduction correcting value, and at the end of the change-speed adjustingthe torque of the input shaft 8, the torque variation of thetransmission output shaft 20 can be suppressed, thereby to improve thespeed changing ability.

[0154] Incidentally, this invention is not intended to be limited to thesystem construction in the above-mentioned embodiments. This inventionis applicable to a control device for a vehicle in which the motor 27 isnot used. Also, it is possible to use as the clutch 4 and the clutch 10all types of friction clutches including a dry type single plate clutch,a wet type multiple plate clutch, an electromagnetic clutch, etc.Further, it is possible to use as the clutch 25 all types of clutchesincluding a dry type single plate clutch, a wet type multiple plateclutch, an electromagnetic clutch, a dog clutch, etc.

[0155] Since this invention is constructed so that any torque variationof the output shaft occurring by the revolution number control carriedout during the change-speed and the torque of the input shaft at the endof the change-speed is adjusted, it is possible to reduce any torquestep of output shaft and suppress any shaft vibration, thereby toimprove speed changing ability for a vehicle,

What is claimed is:
 1. A control device for a vehicle having a torquetransmitting means between the input shaft of a gear type transmissionand the output shaft thereof, the torque transmitting means of at leastone speed changing stage being comprised by a friction clutch, thetorque transmitting means of the other speed changing stages beingcomprised by a dog clutch, and said friction clutch being controlledwhen the change-speed is effected from one speed changing stage to theother changing stage, further comprising; a torque reduction correctingmeans for correcting, at the time of said change-speed, the torquereducing part of said output shaft occurring during the change-speed,and a revolution number controlling means for controlling the revolutionnumber of said input shaft on the basis of the torque reductioncorrecting value corrected by said torque reduction correcting means. 2.A control device as recited in claim 1, further comprising a torqueadjusting means for adjusting the torque of said input shaft at the endof the change-speed on the basis of said torque reduction correctingvalue.
 3. A control method for a vehicle wherein a torque transmittingmeans is attached between the input shaft of a gear type transmissionand the output shaft thereof, the torque transmitting means of at leastone speed changing stage being comprised by a friction clutch, thetorque transmitting means of the other speed changing stages arecomprised by a dog clutch, and said friction clutch being controlledwhen the change-speed is effected from one speed changing stage to theother changing stage, further comprising the steps of; correcting, atthe time of said change-speed, the torque reducing part of said outputshaft occurring during the change-speed, and controlling the revolutionnumber of said input shaft on the basis of the torque reductioncorrecting value corrected by said torque reduction correcting means. 4.A control method as recited in claim 3, further comprising the step ofadjusting the torque of said input shaft at the end of the change-speedon the basis of said torque reduction correcting value.